Vapor-liquid-solid equilibria and thermodynamic study of aluminum chloride aqueous solutions at various temperatures

•Water activity of AlCl3(aq) was measured in the molality and temperature ranges•Osmotic and activity coefficients were evaluated using the Pitzer, EII, and CPB models•Solubility of anhydrous AlCl3was determined experimentally from 298.15 to 353.15 K•Solubility products of AlCl3(aq) were calculated at various temperatures The vapor-liquid-solid equilibria and thermodynamics data relevant to aluminum chloride in aqueous solutions were investigated at various temperatures. The water activity measurements of AlCl3(aq) were carried out from dilution to saturated solutions at temperatures ranging from 298.15 to 353.15 K using the hygrometric method. From new experimental results, the ion interaction of Pitzer, extended ion interaction (EII) and Clegg–Pitzer–Brimblecombe (CPB) models were developed to allow the parametrization of the binary system. The interaction parameters were evaluated for the Al−Cl−H2O system and used to calculate the solute activity and osmotic coefficients form the three models. The standard approach for a 3–1 electrolyte with the ion parameters in the temperature range shows a very good agreement with osmotic coefficient data for unsaturated solutions. The solubility equilibrium of anhydrous AlCl3 in aqueous solutions was determined experimentally up to mmax=(3.383 to 3.606) mol·kg−1from (298.15 to 353.15) K respectively; then, the solubility products as LnKsp∘ of AlCl3(aq) were also given using the obtained activity coefficients at various temperatures. [Display omitted]